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Regulator Problem Or?

MVPILOT

Well Known Member
I have dual Skyviews in my 2015 RV-12 SLSA Rotax 912 ULS. I am concerned about the readings I’m seeing for battery volts and battery amps.

RPM VOLTS AMPS
1850. 12.8. -6
2400. 13.0. -1
3000. 13.4. +5.

Voltage regulator, alternator .....?
 
Last edited:
I don't have dual SkyViews ... but looking at your numbers, I suspect that those readings are typical for a dual SkyView instillation on a Rotax 912 ( which has limited current capabilities from the stator coils at lower RPM's).
 
For the sake of your gearbox on your Rotax, they would like you to keep your RPM's in the 2000 to 2500 range while running, at least until oil is up to temperature.

So I'd go and take voltage and current readings within those RPM ranges.

Some of the Voltage regulators used on RV-12's take up to a half an hour to step up the charging voltage to 14.0 to 14.1V. Find out which model voltage regulator is on your plane, and it's charging voltage characteristics.
 
I agree with John-G. There is no cause for concern. What is the voltage and current at 4000 and 5000 RPM? 13.8 volts or higher is normal above 4000 RPM.
 
The charging system can easily be tested if the load current is known. Because the shunt is in series with the battery we don?t know system load current when the engine is running. So with the engine at operating temperature and the battery fully charged turn the engine OFF. Look at the ammeter, it will be display an nice stable negative value. This is the system load current. Now find the RPM that corresponds to the absolute value of this load current from the graph in section ?2.2.1) Requirements for flawless operation of the rectifier-regulator? of the Installation manual (who says Rotax doesn?t have a sense of humor.) here?s a screenshot
24lkavo.jpg

Start the engine and set the RPM to the value from the graph. Your voltage should stabilize at or above 13.5 volts. The failure mode of the regular is no output or half wave output. A faulty regulator will be obvious by the very low battery voltage displayed.

Thank you. This is very helpful
 
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